1. Field of the Invention
The present invention relates generally to dispensing a fiber optic cable from a vehicle where the cable is used as a data link, for example, and, more particularly, to dispensing of such a cable from a rocket-powered or jet-powered missile directly through the motor exhaust.
2. Description of Related Art
In certain kinds of airborne vehicles, such as a missile, for example, a data link is provided interconnecting the missile control apparatus with other apparatus remaining at the launch site. The data link consists of a length of filament, either a wire or preferably an optical fiber, which is wound onto a canister aboard the vehicle and which upon launch is unwound or dispensed to maintain the data link. In the past, a number of techniques have been employed for the dispensing of such filaments with particular care being devoted to avoid the rocket motor plume which could very quickly destroy the filament. In order to prevent dispensing a filament through the motor exhaust, certain missiles have employed rocket motors with the motor thrust exerted along directions off the missile axis, resulting in a reduction in propulsion efficiency. Other apparatus, while operating the missile drive motors more efficiently along the missile axis, has guided or ducted the optical fiber cable along a path outwardly of the motor plume which is complex and expensive to manufacture as well as subject to imposing a frictional load on the fiber that can destroy the cable or reduce signal transmission efficiency.
It is, therefore, desirable to provide apparatus capable of dispensing a fiber through the rocket or jet motor plume which is reliable, relatively simple to manufacture and use, as well as being cost effective.